公开(公告)号：US20180013484A1

公开(公告)日：2018-01-11

申请号：US15688675

申请日：2017-08-28

申请人： Hughes Network Systems, LLC

发明人： Yash VASAVADA ,  Channasandra RAVISHANKAR ,  Deepak ARUR ,  Michael PARR

IPC分类号： H04B7/185 ,  H04B7/195 ,  H04W56/00

CPC分类号： H04B7/1851 ,  H04B7/185 ,  H04B7/195 ,  H04W56/00

摘要： A method for synchronization of user terminal (UT) uplink data transmissions to a satellite in a satellite communications system is provided. The UT tracks frame timing and frequency of downlink data transmissions received by the UT from the satellite. The UT estimates a respective timing delay and frequency shift of the downlink data transmissions based on the tracked frame timing and frequency of the downlink data transmissions. The UT receives satellite ephemeris data broadcast by the satellite. The UT synchronizes uplink data transmissions to the satellite based on the estimated timing delay and frequency shift of the downlink data transmissions, the received satellite ephemeris data, and knowledge of a UT position and velocity vectors associated with any movement of the UT.

公开(公告)号：US20150270890A1

公开(公告)日：2015-09-24

申请号：US14663442

申请日：2015-03-19

申请人： Hughes Network Systems, LLC

发明人： Yash VASAVADA ,  Channasandra RAVISHANKAR ,  Deepak ARUR ,  Michael PARR

IPC分类号： H04B7/185 ,  H04W56/00

CPC分类号： H04B7/1851 ,  H04B7/185 ,  H04B7/195 ,  H04W56/00

摘要： A synchronization approach is provided that compensates for the large Doppler offset of the satellites in a LEO satellite system by exploiting the predictable and deterministic nature of the Doppler component, and thereby simplifies the delay and the Doppler domain uncertainty ranges that the physical layer receivers have to resolve. The compensation is based on the known ephemeris information of the LEO satellite and the known positions of the gateway (GW) and the user terminal (UT) on the ground. Utilizing the deterministic component of the LEO Doppler, the synchronization process continually tracks and compensates for the time-varying offsets between the GW and UT frame timing, frame numbering (FN), symbol timings, and Doppler-induced scaling of center frequency and the signal bandwidth.

摘要翻译： 提供了同步方法，通过利用多普勒分量的可预测和确定性来补偿LEO卫星系统中卫星的大多普勒偏移，从而简化了物理层接收机必须具有的延迟和多普勒域不确定性范围 解决。 补偿基于LEO卫星的已知星历信息和地面上的网关（GW）和用户终端（UT）的已知位置。 利用LEO多普勒的确定性分量，同步过程连续跟踪和补偿GW与UT帧定时，帧编号（FN），符号定时和中心频率的多普勒引起的缩放之间的时变偏移量 带宽。